1. Field of the Invention
The present invention is generally related to a discharge circuit of an electronic stimulator and more particularly to a discharge circuit of a programmable exciting switching circuit with charge pumps.
2. Description of the Prior Art
The technology of the stimulator devices includes two major categories, one utilizing a transformer as the output element and the other one utilizing a capacitor storing electric charges and then generating an electric output pulse by instant discharge as the output element.
The above two types of output devices both utilize passive elements as the output elements. In the output method of current and voltage, the stimulator device using a transformer as the output element utilizes the analog output method to raise the voltage instantly by the transformer and adjusts its output current and voltage by dividing current in analog circuitry applicable to the stimulator device with larger current amplitude and continuous stimuli. On the other hand, the stimulator device using a capacitor to store electric charges and then discharge instantly utilizes the charging time of the capacitor to control its output current and voltage. By this method, the output of the current and voltage is a bit harder to control. However, it has the advantage of applying in portable or compact stimulator devices for smaller output current amplitude.
In the application of the electronic stimulator, the direction of the discharge needs to be changed or the current amplitude needs to be adjusted dynamically. For instance, the stimulator generally uses two patches as the two discharge electrodes and these two electrodes may be expected to alternating discharge. The period and the intensity of the discharge may need to be altered, such as the intensity of the discharge gradually increases or decreases, or the like.
In order to fulfill the above described requirements, the control of the current or voltage needs to be flexible. Due to the difficulty in specifically controlling the output current and voltage for the stimulator using either a transformer as the output element or a capacitor storing electric charges and discharging instantly, an improved design is required to effectively control the current and voltage, especially for a portable device.